Turkey's Deputy Prime Minister, Hikmet Cetin, pledged yesterday that Turkish troops would end their incursion into Iraq "within weeks" but he refused to set a date for their withdrawal.

"Our military have to reach their objectives and after they have reached them they will withdraw," he said. "We can't set the date, but it will be within weeks."

Mr Cetin was speaking in London after lunch with the Foreign Secretary, Douglas Hurd, as part of Turkey's diplomatic offensive to limit the political damage caused by its campaign against Kurdish guerrillas.

British officials said Mr Hurd repeated Britain's call for an early withdrawal, warned Mr Cetin of the harm done to Turkish relations with Europe and asked for proof of an improvement in human rights.

He reminded the Deputy Prime Minister of the need for Turkey to honour its commitment to safeguard non-combatants and to ensure the delivery of humanitarian aid to the area, according to the official account.

Mr Cetin's said he had found Mr Hurd "very sympathetic." He added: "He understands our position very well."

Britain wishes to strengthen Turkey as a valuable Nato ally and to help to preserve the secular democracy based on the principles of Kemal Ataturk, founder of the modern state.

But the Turkish army's incursion into Iraqi Kurdistan to root out strongholds of the radical PKK, or Kurdish Workers' Party, has caused discomfort in the West. The troops went across the border just after Turkey concluded a customs union with the European Union, a pact which had been delayed by concerns over Turkish policy and must still be ratified by the European Parliament.

Mr Cetin, speaking to his domestic audience in Turkey as well as to the wider world, yesterday gave an uncompromising recital of the Turkish position.

He rejected claims that the incursion violated international law, saying that, in effect, there was a legal vacuum in northern Iraq caused by the creation of a Kurdish "safe haven" north of the 36th parallel. He said the solution was for the Iraqi government to comply with all UN resolutions and so regain its legal authority over the whole of its territory.

Mr Cetin would not acknowledge that Turkey's military campaign against Kurdish extremism was bound to fail if it is not accompanied by political measures to resolve the conflict.

"Terrorism is terrorism," he said. The Deputy Prime Minister refused also to accept that there existed a conflict in Turkey between the government and the Kurdish minorities in the south-east.

"There is no such problem," Mr Cetin said. He ruled out any change in government policy, such as permitting education in the Kurdish language.

"Turkish remains the official language in the schools and that will not change," he said. "If they want to speak or teach their own language privately, that is fine."

Mr Cetin said there was no danger that the military campaign marked a reassertion of the army's power over that of the civilian politicians.

"The government committed itself to democratic reforms and the military action will not affect this," he said. "It has nothing to do with it."